Siegbahn notation

Siegbahn notation is a system used in the field of spectroscopy to designate electronic transitions and the energy levels of atoms, particularly in x-ray spectroscopy. Named after the Swedish physicist Kai Siegbahn, who was awarded the Nobel Prize in Physics in 1981 for his work in this area, the notation provides a systematic way to label the various electron transitions that occur when inner-shell electrons are ejected from an atom.